Method of accelerating the saturation of fabric based sheets with bituminous material



Patented Jan. 9, 1934 UNITED STATES Norman P. Harshberger, Pasadena, Calif., as-

signor to Bakelite Building Products 00., Inc., New York, N. Y., a corporation of Delaware No Drawing. Application April 11, 1930 Serial No. 443,600

5 Claims.

This invention relates to improvements in method of accelerating the saturation of fabric based sheets with bituminous material. Composition roofing material, as commonly used, comprises a fabric base such as felt, which is saturated and coated with a bituminous material such as asphalt, the latter usually having a layer of granulated slate or other mineral sprinkled thereon. Inorder to properly waterproof the felt base, it is necessary that the asphalt saturant thoroughly penetrate the fibers of said felt base. Heretofore, it has been difficult to obtain a thorough saturation in a sufficiently short period of time to enable the remaining steps in manufacturing the roofing to be carried out without interruption.

It is, therefore, one of the objects of the present invention to provide a method of accelerating the saturation of fabric based sheets with bituminous material in which the penetration of the bituminous material into the fibres of the base takes place in a relatively short period of time.

A more specific object of this invention is to provide an improved method of the class described in which the fabric base is treated with a starch-like emulsion prior to the application of the bituminous material, the said emulsion, due to its capability of forming a smooth, slip pery coating when dry, tending to act as a vehicle for rapidly carrying the saturant through the sheet so that it will thoroughly penetrate the fibres thereof.

With the above and other objects in view, the invention consists of the improved method of ac-- celerating the saturation of fabric based sheets with bituminous material, and all its parts and combinations, as set forth in the claims, and all equivalents thereof.

In carrying out the method according to the preferred manner, a sheet of felt which has been manufactured from wool or cotton rags and paper, is dipped into an emulsion. Said emulsion may comprise vegetable starch, bentonite, soapstone, or a liquid of a similar nature capable of forming a smooth, slippery coating when dry. If desired, the emulsion may be applied to the felt during the process of manufacture of the latter.

After the felt has been treated as above de- PATENT OFFICE scribed, it is relieved of moisture preferably by passing the sheet over a heated roll. Next, a coating of bituminous material, such as liquid asphalt is applied to the felt, and due to the fact that the emulsion of starch has formed a smooth 5 coating upon each fibre of the felt, the asphalt will penetrate very thoroughly and rapidly to effectively waterproof the material. To complete the roofing sheet, heavier coating material is applied and a layer of mineral material such as crushed slate is sprinkled over the asphalt coating and is partially embedded therein.

From the foregoing description, it may read ily be seen that the improved method is simple to carry out, and is well adapted for the purpose of accelerating the saturation of the felt base with bituminous material.

What I claim is:

1. The method of manufacturing composition roofing consisting of treating a sheet of felt with 7 a solution of starch which when dry will form a smooth coating on the fibres of said felt, and then applying a bituminous waterproofing material to the felt sheet thus treated, said waterproofing material quickly penetrating the fibres of the sheet due to the smooth coating thereon.

2. The method of manufacturing composition roofing consisting of treating a sheet of felt with a solution of starch which when dry will form a smooth coating on the fibres of said felt, and then applying an asphalt waterproofing material to the felt sheet thus treated, said waterproofing material quickly penetrating the fibres of the sheet due to the smooth coating thereon.

3. The method of manufacturing composition roofing, consisting of dipping a sheet of felt into a solution of starch which when dry will form a smooth-coating on the fibres of the felt, applying a bituminous waterproofing material to the felt sheet thus treated, said waterproofing material quickly penetrating the fibres of the felt sheet due to the smooth coating thereon, and applying a layer of crushed mineral to said 'waterproofing material.

4. In a method of manufacturing composition roofing material to be applied to a building, the steps of providing a fibrous web, coating the surface of the fibers with a fluid containing a solid substance that will act as a vehicle for a bituminous saturant, heating the web to dry said coating and leave a dried residuum of said substance, and thereafter applying a bituminous material to said web, the coating on the fibers of said web serving to accelerate the penetration of said bi- 5 tuminous material into said web.

5. The method of manufacturing waterproof saturated composition roofing material to be applied to a building comprising coating the fibres of a web of felted material with an accelerating vehicle for its saturant by dipping in a fiuid containing said vehicle and a volatile liquid, applying heat to drive ofi the volatile constituent and thereafter saturating said coated web with a bituminous material, said vehicle serving to quickly convey said bituminous material into said web.

NORMAN P. HARSHBERGER. 

